However, it looks that that room actually has a regular floor
Look carefully at the picture, he's not standing on a solid floor, he's standing on a wire frame over more absorbers. Their website has a better pic: http://www.orfieldlabs.com/Researchtour4.html
IOW, their chamber is (fully) anechoic, not just hemi-anechoic.
Yes, you're quite right; I thought that was a particularly ugly patterned carpet he was standing on. I think that says more about British carpets than anything else :)
Looks like their wire floor is a bit more permanent than the design I was using; my microphone was on a rotating boom that could be swept 360 degrees from outside, and my sample mounting was a pole down to the real floor, so we could have the absolute minimum of interference from the mountings.
Look carefully at the picture, he's not standing on a solid floor, he's standing on a wire frame over more absorbers. Their website has a better pic: http://www.orfieldlabs.com/Researchtour4.html
IOW, their chamber is (fully) anechoic, not just hemi-anechoic.